Q: dba_registry_history vs dba_registry_sqlpatch and OJVM patch Should dba_registry_sqlpatch-view list all installed patches and therefore it would also list OJVM patches?
Or OJVM patches are only listed in dba_registry_history-view?

A: If the database was patched properly, DBA_REGISTRY_SQLPATCH should list the OJVM patch. Below output is from one of my sandbox environments:
SQL> select DESCRIPTION, ACTION, STATUS, ACTION_TIME from dba_registry_sqlpatch;

DESCRIPTION                                                       ACTION          STATUS          ACTION_TIME
----------------------------------------------------------------- --------------- --------------- --------------------
Database PSU 12.1.0.2.190716, Oracle JavaVM Component (JUL2019)   APPLY           SUCCESS         2019-10-01 15:31:58
DATABASE PATCH SET UPDATE 12.1.0.2.190716                         APPLY           SUCCESS         2019-10-01 15:31:59

SQL> select comments from dba_registry_history;

COMMENTS
--------------------------------------------------------------------------------
RDBMS_12.1.0.2.0DBPSU_LINUX.X64_161210

